TCT-656 Prolong Blood Stasis on Transcatheter Aortic Valve Leaflets as a Possible Mechanism for Thrombogenesis (original) (raw)
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Blood Stasis on Transcatheter Valve Leaflets and Implications for Valve-in-Valve Leaflet Thrombosis
The Annals of thoracic surgery, 2017
Leaflet thrombosis after valve-in-valve (ViV) procedure has been increasingly recognized. This study aimed to investigate the flow dynamics aspect of leaflet thrombosis by quantifying the blood stasis on the noncoronary and coronary leaflets of a surgical aortic valve (SAV) and a transcatheter aortic valve (TAV) in a ViV setting. Two computational models, representing a SAV and a TAV in ViV setting, were developed in a patient-specific geometry. Three-dimensional flow fields were obtained through a fluid-solid interaction modeling approach to study the difference in blood residence time (BRT) on the coronary and noncoronary leaflets. Longer BRT was observed on the TAV leaflets compared with the SAV, specifically near the leaflet fixed boundary. Particularly, at the end of diastole, the areas of high BRT (≥1.2 seconds) on the surface of the TAV model leaflets were four times larger than those of the SAV model. The distribution of BRT on the three leaflets exhibited a similar pattern ...
Lancet (London, England), 2017
Subclinical leaflet thrombosis of bioprosthetic aortic valves after transcatheter valve replacement (TAVR) and surgical aortic valve replacement (SAVR) has been found with CT imaging. The objective of this study was to report the prevalence of subclinical leaflet thrombosis in surgical and transcatheter aortic valves and the effect of novel oral anticoagulants (NOACs) on the subclinical leaflet thrombosis and subsequent valve haemodynamics and clinical outcomes on the basis of two registries of patients who had CT imaging done after TAVR or SAVR. Patients enrolled between Dec 22, 2014, and Jan 18, 2017, in the RESOLVE registry, and between June 2, 2014, and Sept 28, 2016, in the SAVORY registry, had CT imaging done with a dedicated four-dimensional volume-rendered imaging protocol at varying intervals after TAVR and SAVR. We defined subclinical leaflet thrombosis as the presence of reduced leaflet motion, along with corresponding hypoattenuating lesions shown with CT. We collected d...
Vascular approaches and its potential implications in transcatheter aortic valve implantation
Vessel Plus
Transcatheter aortic valve implantation (TAVI) has become in the last years a primary therapeutic tool in order to treat percutaneously severe aortic stenosis in frail patients with multiple comorbidity and a high surgical risk. In almost all cases, the complexity of patients who are candidates for TAVI is also reflected in challenging access sites. This vascular issue addresses the invasive play of constantly evolving devices and resulting complications have a considerable impact on patient morbidity and mortality. For this reason, the study and the choice of the different access site require the attention and experience of the operators to reach the most reliable and feasible vascular approach for a real procedural success.
Role of different vascular approaches on transcatheter aortic valve implantation outcome
Journal of Cardiovascular Medicine, 2015
Objective To compare different vascular approaches on clinical outcome of patients undergoing transcatheter aortic valve implantation (TAVI) with self-expandable bioprosthesis. Methods We included all the patients undergoing CoreValve implantation at our institute between September 2007 and March 2014. They were divided into four groups based on the vascular approach: percutaneous transfemoral (pTF), cut-down transfemoral (cTF), transaxillary (TAx) and transaortic (TAo). Clinical outcomes were evaluated according to Valve Academic Research Consortium-2 recommendations. Results Out of 322 consecutive patients, 170 (53%) underwent pTF, 76 (23%) cTF, 32 (10%) TAx and 44 (14%) TAo approach. Although the TAx and TAo patients had a higher risk profile, they had a similar outcome compared with the pTF and cTF groups; in particular, there were no differences regarding cardiovascular and all-cause mortality at 30 days, 1 and 2 years, as well as stroke, myocardial infarction, bleeding, major vascular complications, permanent pacemaker implantation and acute kidney injury rates. The observed device success rate was higher in the TAo than in the other approaches (88.6 versus 65.9, 68.7 and 76.3% in the pTF, cTF and TAx groups, respectively; P U 0.019). No differences occurred regarding 30-day early safety and 1-year clinical efficacy across the four groups. Fluoroscopy time, amount of contrast medium used and minor vascular complications were significantly higher in pTF patients, as well as in-hospital stay in the TAo group. Atrial fibrillation and prosthetic valve regurgitation, but not the vascular approach, were independent predictors of all-cause mortality. Conclusion A more invasive vascular approach, for CoreValve implantation, even in higher risk patients, does not affect early-term, mid-term and long-term outcomes.
Aortic Flow Patterns After Simulated Implantation of Transcatheter Aortic Valves
Hellenic journal of cardiology : HJC = Hellēnikē kardiologikē epitheōrēsē
The functional behavior and hemodynamic characteristics of percutaneously implanted bioprosthetic valves are not known. We created aortic models after the simulated implantation of two of the most widely used bioprosthetic valves: the Edwards SAPIEN, and the Medtronic CoreValve. By using computational fluid dynamics analysis we sought to investigate variations in the aortic flow patterns induced by the two valve designs and their association with detrimental phenomena such as vascular remodeling, vascular wall damage and thrombosis. The simulated implantation of models that resemble the two valves resulted in different aortic flow conditions. Vortex formation in the upper ascending aorta was more persistent in the case of the simulated Medtronic valve. The ranges of average wall shear stress (WSS) values were 2.4-3.5 Pa for Edwards and 3.0-5.3 Pa for Medtronic; the calculated WSS values induced endothelial quiescence and an atheroprotective setting in both valves. The average shear ...
Valve-in-Valve Hemodynamics of 20-mm Transcatheter Aortic Valves in Small Bioprostheses
The Annals of Thoracic Surgery, 2011
Background. Transcatheter aortic valve (TAV) implantation is a treatment for selected patients with failing bioprostheses. We previously showed that currently available SAPIEN (Edwards Lifesciences, Irvine, CA) TAV sizes did not yield acceptable valve-in-valve (VIV) hemodynamics in small degenerated bioprostheses because optimal TAV function requires full stent expansion to its nominal size. The study objective was to determine (1) if 20-mm TAVs provide acceptable hemodynamics in small degenerated bioprostheses and (2) the effect of TAV spatial orientation on valvular hemodynamics and coronary flows.
Journal of Clinical Medicine
Transcatheter aortic valve implantation (TAVI) is a recent revolutionary treatment for high-risk patients with severe aortic stenosis who are not suitable for surgery, expanding to intermediate and low-risk patients. Valve leaflet thrombosis (LT) is a potentially fatal complication after TAVI. The incidence of subclinical LT is as high as 25% among patients in the first year after TAVI. Subclinical LT may evolve into symptomatic thrombosis or lead to premature bioprosthesis degeneration, increasing the risk of neurological complications. Because imaging-based methods have limited sensitivity to detect subclinical LT, there is an urgent need for predictors and biomarkers that would make it possible to predict LT after TAVI. Here, we summarize recent data regarding (i) patient-related, (ii) procedure-related, (iii) blood-based and (iv) imaging predictors and biomarkers which might be useful for the early diagnosis of subclinical LT after TAVI. Prevention of LT might offer an opportuni...